A girl stands by a closed storage area where a poster hangs of Venezuela's President Hugo Chavez in Caracas, Venezuela, Friday, April 20, 2012. Chavez is in Cuba to continue with cancer treatment. (AP Photo/Ariana Cubillos)— AP

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A girl stands by a closed storage area where a poster hangs of Venezuela's President Hugo Chavez in Caracas, Venezuela, Friday, April 20, 2012. Chavez is in Cuba to continue with cancer treatment. (AP Photo/Ariana Cubillos)
/ AP

CARACAS, Venezuela 
Venezuelan President Hugo Chavez has been out of sight for a week, speaking only through Twitter messages and written statements while undergoing cancer treatment in Cuba.

The lack of any appearances on television has Venezuelans wondering about what his unusual silence might say about his struggle with cancer, and whether Chavez may be coping with a particularly tough phase of radiation therapy.

More than two dozen messages have appeared on Chavez's Twitter account since he left for Cuba on April 14. He has cheered on his supporters with slogans such as, "Let's continue building socialism!"

In other messages, he has praised his military commanders, announced funding for local governments and vowed to survive and win re-election in October. But he has seldom mentioned his cancer treatment.

National Assembly President Diosdado Cabello reiterated on Friday that Chavez is expected to return to Venezuela soon.

"God willing, next week he'll be here again with us once he has finished the treatment," Cabello said in a televised speech. He insisted that even when Chavez is away in Cuba, "he leads just the same as if he were here in Venezuela."

"The commander's presence here isn't necessary because just the same he's the commander of the revolution," Cabello said.

But even some of Chavez's supporters have been saying recently that they wonder what's really going on with his health.

"It makes me sad, but my Comandante must not be as well as they say," said Guillermo Suarez, a street vendor selling sunglasses. "It's already been many days that we haven't seen him, heard him."

Chavez, who has been in office in 1999, has long been a constant presence on Venezuelan television, often addressing the nation for several hours most days in addition to his marathon Sunday program "Hello, President." But recently there have been no episodes of "Hello, President," and Chavez had said that he expected his final rounds of radiation treatments, which began last month, to be rough.

He has said the treatments have diminished his physical strength. Last weekend, he decided not to attend the Summit of the Americas in Colombia, the sort of high-profile international event where he would previously have taken center stage. Foreign Minister Nicolas Maduro announced the decision on Chavez's behalf, saying he was skipping the summit on the advice of his doctors.

Chavez began radiation treatment in Cuba in late March after undergoing an operation in February that removed a second tumor from his pelvic region. The first was taken out last June. He has kept secret some details of his illness, including the type of cancer and the precise location of the tumors.